Headrest assemblies, for particular use in conjunction with vehicle seats, often include a number of adjustable features that may be powered or manually adjusted. Such headrest assemblies may be bulky and expensive in order to provide the adjustability necessary to meet the needs of a multitude of users. In the vehicle industry, various trim levels call for upgraded features, including headrest assemblies having enhanced comfort features. As such, a modular headrest assembly that can be used with a variety of trim levels within a vehicle is desired.